The present invention relates to methods for the preparation of polyesters, poly(ester amide)s and poly(ester imide)s. The materials obtained by the methods of present invention are useful as fluid separation membranes and as high performance materials.
Polymers containing the ester linkage, such as polyesters, poly(ester amide)s, and poly(ester imide)s have been extensively studied and used in variety of applications. General information about the polymers containing the ester linkages can be found in the following and other monographs and reviews: P. E. Cassidy, xe2x80x9cThermally Stable Polymersxe2x80x9d, Marcel Dekker, 1980.
R. A. Gaudiana, et al., xe2x80x9cProgress in Polymer Sciencexe2x80x9d, Volume 14, page 47-89, 1989. H. R. Kricheldorf, xe2x80x9cHandbook of Polymer Synthesisxe2x80x9d, Marcel Dekker, 1992.
F. Millich, C. E. Carraher, Jr., xe2x80x9cInterfacial Synthesisxe2x80x9d, Marcel Dekker, 1977.
Interfacial polymerization and high temperature melt polymerization methods are two commonly used methods for the preparation of polyesters. Although both methods provide sufficient high molecular weight polyesters, the interfacial polymerization method uses large amount of chlorinated solvents and melt polymerization method uses very high polymerization temperature (under the conditions of pyrolysis). The direct polymerization between aromatic dicarboxylic acids and diols was reported by Higashi et al in xe2x80x9cJournal of Polymer Science, Polymer Chemistry Editionxe2x80x9d, Volume 23, page 1361, 1985. The method used pyridine as the polymerization media and the polymerization temperature needed to be higher than 100xc2x0 C.
The low temperature solution polymerization method between an aromatic dicarboxylic chloride and a diol is well known in the art but it affords only low molecular weight oligomers, see for example, H. Jeong et al. in xe2x80x9cJournal of Polymer Science, Polymer Chemistry Editionxe2x80x9d, Volume 32, page 1057, 1994; Y.-T. Chern, in xe2x80x9cMacromoleculesxe2x80x9d, Volume 28, page 5561, 1995; and M. Bruma, et al. in xe2x80x9cJournal of Macromolecular Science, Review of Macromolecular Chemistry and Physicsxe2x80x9d, Volume C36, page 119, 1996.
U.S. Pat. No. 4,387,210 disclosed the synthesis of selected poly(etser amide)s from aminophenols by interfacial polymerization reaction. Due to the significant solubility differences between aromatic diamines and the salts of aromatic diols, the preparation of poly(ester amide)s by interfacial polymerization starting from an aromatic diamine and an aromatic diol is very difficult to practice. U.S. Pat. Nos. 3,859,251, 4,075,179 and 5,243,017 disclosed certain poly(ester amide)s prepared by melt polymerization method at high temperature under vacuum.
The synthesis of poly(ester imide)s is known in the art. For example, U.S. Pat. Nos. 4,631,333; 4,383,105 and 3,542,731 describe processes in which the monomeric trimellitic acid imide is first prepared from trimellitic acid anhydride and aminophenol and then is polymerized under conditions of pyrolysis. U.S. Pat. Nos. 5,349,039 and 5,708,122 describe a processes in which the monomeric imide diacid is first prepared from trimellitic acid anhydride and a dianiline or aminobenzoic acid and then poly(ester imide)s are obtained by polymerization with a bisphenol. Wang and Yang describe the process in which a monomeric ester dianiline is first prepared and then is polymerized with a dianhydride, see, Polymer Preprint, American Chemical Society, Volume 39(2), 1998, page 800. Loncrini describes a process in which a monomeric ester dianhydride is first synthesized and isolated and then is polymerized with a dianiline, see, Journal of Polymer Science, Part A-1, Volume 4, page 1531, 1966. All processes disclosed so far either involve the isolation and purification of the intermediate monomers or use very high polymerization temperature (under the conditions of pyrolysis).
Accordingly, one object of the present invention is to provide a novel low temperature solution polymerization method for the preparation of polyesters.
Another object of the present invention is to provide a novel low temperature solution polymerization method for the preparation of poly(ester amide)s.
The invention comprises a novel low temperature solution polymerization method for the preparation of polyesters and poly(ester amide)s.
One embodiment is a novel one-pot process for the preparation of poly(ester imide)s with the general formula I by reacting an anhydride chloride with a diol and a diamine. 
Where x is an integer larger than 10.
Another embodiment of the present invention provides improved catalysts to catalyze the formation of ester linkage in a polymerization reaction.
Another embodiment provides catalysts to catalyze the formation of ester anhydride and the formation of high molecular weight poly(ester imide)s therefrom in one-pot reaction.
Still another embodiment of the present invention provides a process to form novel soluble polyamic acids and derivatives therefrom, in particular polyester amic acid salts.
A further embodiment of the present invention provides novel soluble poly(ester amide)s and poly(ester imide)s derived from the following diols. 
where n=0xe2x88x922 and R is:
xe2x80x94H, xe2x80x94CH3, xe2x80x94CH2CH3, xe2x80x94CH2CH2CH3, iso-propyl, iso-butyl, tert-butyl, xe2x80x94Br, xe2x80x94Cl, xe2x80x94F, xe2x80x94NO2, xe2x80x94CN, 
Z and Zxe2x80x2 are: 
Still a further embodiment of the present invention provides novel poly(ester amide) and poly(ester imide) polymeric fluid separation membrane materials with improved separation characteristics.